High mobility CMOS using germanium (Ge) as a channel material may utilize relaxed germanium for NMOS devices and strained germanium on a silicon germanium (SiGe) strain relaxed buffer layer for PMOS devices. It is a major technical challenge to integrate both materials together on a common substrate with low defect levels.
Some vertical nanowire or vertical FET devices utilize relaxed germanium as a channel material in PMOS devices while silicon may be used for channel material in NMOS devices.
There exists a need in industry for manufacturing methods which allow combining two different channel materials or channel strain states on a common base substrate.